Anaphylaxis and other adverse events
Aim: To be able to manage anaphylaxis and other adverse events correctly
Learning outcomes Define local and systemic adverse events Distinguish between anaphylaxis and fainting Manage anaphylaxis Prepare and check the equipment and drugs used for managing anaphylaxis Define and recognise an adverse event Report an adverse event
Classification of Adverse Events Following Immunisation (AEFI) Vaccine-induced AEFI Induced direct effects of vaccine or vaccine component and/or due to underlying medical condition or idiosyncratic response in recipient Programmatic errors Incorrect doses or routes, wrong diluent Coincidental events Chance happening Injection reaction Result of injection itself, not the vaccine e.g. pain, anxiety Unknown Cause cannot be determined
Types of adverse event Local Reactions More common with non-live vaccines containing adjuvants (Pain, redness, swelling at injection site) Systemic Reactions Generally more common following live vaccine, but less severe with subsequent doses (Fever, headache, loss of appetite) Allergic Reaction Anaphylaxis/Severe systemic allergic reaction
Systems for monitoring/reporting AEFI Yellow card System Passive reporting by doctor, pharmacist, nurse, patient or parent to the Medicine and Healthcare Products Regulatory Agency (MHRA) http://medicines.mhra.gov.uk/ Immunisation programme / public health agency Special schemes (specific condition) e.g.. British Paediatric Surveillance Unit (BPSU) in UK
What is anaphylaxis? Definition of anaphylaxis Typically rapid and unpredictable with variable severity and clinical features including cardiovascular collapse, bronchospasm, angioedema, pulmonary oedema, loss of consciousness and urticaria Potentially life threatening AEFI One of four types of hypersensitivity reactions Very rare - approx one per million vaccine doses (Bohlke et al. Risk of Anaphylaxis After Vaccination of Children and Adolescents Pediatrics 2003; 112:815-820)
What happens during anaphylaxis Essentially an inappropriate immune response Occurs as a result of exposure to an allergen to which a person has been sensitised and previously made specific immunoglobulin E (IgE) Anaphylaxis can occur on re-exposure to the antigen when explosive amounts of histamine and other chemical mediators are released following the binding of the antigen to IgE coated mast cells.
Potential triggers Various common food and non food triggers (Nuts, shellfish, dairy products, wasp or bee stings, latex, antibiotics, antiinflammatories) Vaccine specific Egg proteins (yellow fever and influenza vaccines) Thiomersal (some flu and hep B vaccines) Antibiotics (Neomycin streptomycin and polymixin B) Toxoid (DTaP, Td) Stabilisers and other vaccine components (Yeast, gelatin)
Distinguishing signs and symptoms of anaphylaxis and a faint: In groups list the signs and symptoms of anaphylaxis and a faint Cardiovascular system Respiratory system Gastrointestinal tract Skin Central nervous system
ABCDE Airway swelling of tongue, throat Difficulty breathing Hoarse voice, stridor Breathing shortness of breath Increased respiratory rate Wheeze Hypoxia confusion Respiratory arrest
Circulation Signs of shock Pale, clammy, tachycardia, hypotension Decreased conscious level Cardiac arrest Do not stand patient up
Disability sense of impending doom Anxiety, panic Decreased conscious level Exposure skin changes in over 80% Erythema / Uticaria Includes mucosal changes - Angiodema
Signs & Symptoms Mild Flushed Appearance Urticaria Anxiety Headache Nausea Abdominal pain
Signs & Symptoms Moderate Feeling of Impending Doom! Swelling Dyspnoea Wheeze Stridor Tachycardia Classic features of Moderate Anaphylactic reaction - Swelling of lips - Urticaria
Signs & Symptoms Severe Angioedema (Including Pharyngeal/Laryngeal) Hypotension Cyanosis Collapse Respiratory or cardiac arrest DEATH!!!
Management of anaphylaxis Call for assistance Lie patient down with legs raised (unless breathing difficulties) Where available administer oxygen (10-15 Litre/min) If showing clinical signs of shock, difficulty breathing or deteriorating consciousness administer intramuscular adrenaline into anterolateral aspect of thigh Repeat dose if no clinical improvement Age Less than 6 mths 6 months- 6 yrs 6-12 years Over 12 years Dose of adrenaline 1:1000 (1mg/ml) 0.15ml 0.15ml 0.3ml 0.5ml or 0.3ml (if small or prepubertal)
Minimum slide set created by: Immunisation Department, Centre for Infections, Health Protection Agency to assist teaching of the Core Curriculum for Immunisation Training (see http://www.hpa.org.uk/infections/topics_az/vaccination/training_menu.htm)